Have you ever consider an online school for girls? How about The Online School for Girls? It is located in Nashville, TN and was originally a collaboration of Harpeth Hall School (Nashville, TN), Holton-Arms School (Bethesda, MD), Laurel School (Cleveland, OH), and Westover School (Middlebury, CT). It has now grown to include many additional schools. If you would like to get some idea of what is offered at OSG, see the video below.
Also, a new (to me) school is the Online School for Boys. Should have it up on the website soon.